1. Field of the Invention
This invention relates to a process for the preparation of o-alkoxyphenols from substituted cycloaliphatic compounds, such as 2-chlorocyclohexanone, by conversion of the chloroketone to the alkoxyketone and dehydrogenation thereof by contact with a Group VIII noble metal catalyst.
2. Prior Art Relating to the Disclosure
O-methoxyphenol (guaiacol) and o-ethoxyphenol have many uses as intermediates in organic synthesis, O-methoxyphenol is also useful as a reagent in detecting lignin and, medicinally as an antiseptic.
It is known that alicyclic ketones dehydrogenate to phenols by catalytic means as described, for example, in the following U.S. Pat. Nos. 2,321,551; 2,503,641; 2,588,359; 2,628,985; 2,708,208; 3,256,348; 3,345,382; 3,358;044; 3,391,199; 3,514,492; and 3,534,110. It is also known that cyclohexanediols can be catalytically dehydrogenated to yield phenol and pyrocatechol Catalytic dehydrogenation of 2-hydroxycyclohexanone or cyclohexane, 1, 2-dione in the liquid phase to pyrocatechol by contact with a noble metal catalyst is described in Belgian patent No. 763,803.
Preparation of 2-methoxy-cyclohexanone from 2-hydroxycyclohexanone is reported in the literature; M. Bergmans and M. Gierth, Ann. 448, 48(1926) and H. W. Durbeck, C. G. B. Frishkorn and K. Hilpert, Tetrahedron 27,2927 (1971).